2001 GAGT1 power steering problems

I was driving the car really hard this one day and after the first time I parked it the power steering started acting up.

When the engine is idling or in the low rpms the power steering is practically off, when I rev it a bit or am driving 2.5k+ rpm it's fine.

I checked the power steering fluid level was perfect, and no leaks.

I'm thinking something in the ECU/PCM got thrown off i.e. what ever values dictate steering force requiered for any speed.

Any Ideas?

do you have the variable rate steering on your car? Look at your veh ident label in the trunk, if you have code "N40" you do not have variable rate steering, if you have code "NV7" you do. IF you don't have variable assist, the problem is more than likely the check valve at the pump, dealer only (GM#7846645 $25). If you have variable assist, there is a sensor in the pump that is probably your problem, It's a dealer only part, GM # 26071772 and runs about $150.

I do have the variable rate steering; and a faulty or thrown off sensor does fit the symtom bill; I'll check it out.